This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-106972, filed Apr. 7, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a single-substrate-heat-processing apparatus for performing a semiconductor process, such as oxidation, diffusion, CVD (Chemical Vapor Deposition), or annealing. The term xe2x80x9csemiconductor processxe2x80x9d used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target substrate, such as a semiconductor wafer or an LCD substrate, by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target substrate.
In the process of manufacturing semiconductor devices, several types of heat-processing apparatuses are used for subjecting target substrates, such as semiconductor wafers, to a semiconductor process, such as oxidation, diffusion, CVD (Chemical Vapor Deposition), or annealing. A single-substrate-heat-processing apparatus, which handles wafers one by one, is known as one of these heat-processing apparatuses. The single-substrate-heat-processing apparatus allows a heat process to be relatively easily performed with a high planer uniformity on a wafer, even when the heat process requires the process temperature to be raised and lowered quickly. For this reason, the single-substrate-heat-processing apparatus has become popular, as the size of wafers has been larger, and the size of semiconductor devices has been smaller.
The single-substrate-heat-processing apparatus generally includes an airtight process chamber, and a worktable disposed in the process chamber for mounting a target substrate, such as a semiconductor wafer, wherein the wafer is generally heated by the worktable. The heat in the wafer and the worktable is discharged more from their peripheries, and thus the temperature at the periphery of the wafer becomes lower than that at the center. If such non-uniformity in temperature is generated on the wafer, the planar uniformity in the heat process is lowered, and, for example, in a film formation process, the thickness of the formed film becomes uneven. This problem is more serious in a single-substrate-heat-processing apparatus of the lamp-heating type, in which a wafer is heated by lamps disposed below a worktable.
An object of the present invention is to provide a single-substrate-heat-processing apparatus for a semiconductor process, which allows a target substrate, such as a wafer, to be uniformly heated, and thus allows a process to be performed with a high planar uniformity.
According to a first aspect of the present invention, there is provided a single-substrate-heat-processing apparatus for performing a semiconductor process, comprising:
an airtight process chamber;
a mount plate configured to support a target substrate within the process chamber, the mount plate consisting essentially of one or more material selected from the group consisting of silicon carbide, aluminum nitride, black aluminum nitride, and carbon coated with CVD-SiC;
a metal support frame configured to support the mount plate;
an isolator intervening between the mount plate and the support frame to substantially prevent the mount plate and the support frame from coming into direct contact with each other, the isolator consisting essentially of one or more material selected from the group consisting of aluminum oxide, aluminum nitride, silicon nitride, silicon oxide, and zirconia;
a supply section configured to supply a process gas into the process chamber;
an exhaust section configured to vacuum-exhaust the process chamber; and
a heater configured to heat the target substrate on the mount plate.
According to a second aspect of the present invention, there is provided a single-substrate-heat-processing apparatus for performing a semiconductor process, comprising:
an airtight process chamber;
a metal shield frame partitioning the process chamber into a process space on an upper side and a lower space on a lower side, the shield plate having an opening and an inwardly extending portion extending in the opening;
amount plate configured to support a target substrate within the process space, the mount plate consisting essentially of one or more material selected from the group consisting of silicon carbide, aluminum nitride, black aluminum nitride, and carbon coated with CVD-SiC, and mounted on the inwardly extending portion to partition the process chamber into the process space and the lower space;
an isolator intervening between the mount plate and the shield frame to substantially prevent the mount plate and the shield frame from coming into direct contact with each other, the isolator consisting essentially of one or more material selected from the group consisting of aluminum oxide, aluminum nitride, silicon nitride, silicon oxide, and zirconia, wherein the isolator comprises a lower member mounted on the inwardly extending portion, and an upper member formed independently of the lower member and mounted on the lower member, and the upper member comprises an outer cover portion covering an inner edge of the shield frame to prevent the process gas from entering downward, and an inner cover portion covering an outer edge of the mount plate to prevent the process gas from entering downward and to restrict movement of the mount plate in a vertical direction;
a supply section configured to supply a process gas into the process space;
an exhaust section configured to vacuum-exhaust the process chamber; and
a heating lamp disposed below the mount plate to radiate light onto the mount plate, thereby heating the target substrate on the mount plate.
According to a third aspect of the present invention, there is provided a single-substrate-heat-processing apparatus for performing a semiconductor process, comprising:
an airtight process chamber;
a metal shield frame partitioning the process chamber into a process space on an upper side and a lower space on a lower side, the shield plate having an opening and an inwardly extending portion extending in the opening;
a mount plate configured to support a target substrate within the process space, the mount plate being mounted on the inwardly extending portion to partition the process chamber into the process space and the lower space;
an isolator intervening between the mount plate and the shield frame to substantially prevent the mount plate and the shield frame from coming into direct contact with each other, the isolator consisting essentially of a material having a thermal conductivity lower than that of the mount plate;
a supply section configured to supply a process gas into the process space;
an exhaust section configured to vacuum-exhaust the process chamber;
a plurality of lifter pins disposed in the lower space, for assisting load and unload of the target substrate relative to the mount plate, and configured to project and retreat relative to the mount plate through holes formed in the mount plate;
a heating lamp disposed at a position outside the process chamber and below the mount plate to radiate light onto the mount plate, thereby heating the target substrate on the mount plate; and
a window formed in a wall of the process chamber to face the heating lamp, and configured to allow the light from the heating lamp to pass through.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.